MR DAVID MILNE HOME ON THE BOULDER-CLAY OF EUROPE. 6Q7 



curious to investigate, whether this smoothness could be traced to any external 

 cause such as that observed by Sir James Hall, on Corstorphine Hill." At an 

 early period geologists were unacquainted with the abrading effects of ice. 

 From Mr Allan's description of the markings on the hill at Eide, and from its 

 situation on the N.W. coast of Faroe, it is not difficult to see the agency of 

 icebergs. 



In Iceland the striae, as Dr Chambers states in his instructive little book,* 

 run N. 30° W. (true). Having endeavoured, through my friend, Mr R. M. Smith 

 of Leith, who has correspondents in the island, to obtain farther information 

 regarding the markings on the rocks, I have had sent to me by Mr Smith the 

 following extract from a letter by Dr Hjaltelin, of Reykavik, Knight of the 

 Dannebrog, and principal physician in the island : — " The diluvial scratches are 

 to be seen everywhere in the south part of our country. They run in lines 

 parallel to one another, and can scarcely be occasioned by the action of rain or 

 water. Their direction is very much against this view. You see them on the 

 slope of the hills, not following the declivity of the rocks, but everywhere run- 

 ning in the well-known direction from N.W. to S.E., in spite of the declivity. 

 Many of these scratches are very unequal, and seem evidently to have been pro- 

 duced by a hard material gliding over the rocks in the aforesaid direction. It 

 must furthermore be remarked, that these furrows, which are unequal both in 

 depth and diameter, could hardly have such a regular parallel direction, if 

 occasioned by water or rain. 



" These scratches are all round here in our mountains. In the lower flat lava- 

 fields, some deep and broad irregular scratches may also be seen ; but they have 

 no constant direction, and seem to have been produced by pieces ' of hard material 

 gliding over the lava when still in a soft condition.' " f 



In Sweden, the markings on the rocks show a movement generally from the 

 N.N. W., which is also the direction of the b'sars or elongated gravel ridges, so 

 abundant in that country. 



In Finland, on the Gulf of Bothnia, and on the Lake of Ladoga, in Russia, the 

 direction is N.W. 



In Denmark (as Forschammer shows), the markings on the rocks show a move- 

 ment from W. 25° N. (true). The following case mentioned by him at Gothenburg 

 (situated near the southern extremity of Sweden) leaves little doubt regarding 

 the nature of the agent which made the markings. There was a large furrow or 

 rut on a rock, the prolongation of which rut had been arrested or prevented by a 

 boulder lying on the rock and firmly jammed. The boulder was about 3 feet 

 thick vertically; and on its upper surface there was a rut, which being exactly 

 in a line with the rut on the rock, seemed to have been made by the same agent, 



* Voyage to Iceland and the Faroe Isles. 



\ Letter from Dr Hjaltelin, Knight of the Dannehrog, and Chief Physician in Iceland. 



VOL. XXV. PART II. 8 L 



